The statements in this section merely provide background information related to the present disclosure and may or may not constitute prior art.
Automatic transmissions provide a plurality of forward and reverse speed or gear ratios by selectively actuating one or more brakes or clutches. One type of brake or clutch useful in automatic transmissions is known as a selectable one-way clutch. A selectable one-way clutch is similar to a basic one-way clutch, which includes a “locked” mode in one rotational direction and a “freewheel” mode in the opposite rotational direction. In the basic one-way clutch, the operating mode is determined by the direction of the torque being applied to the input member. A selectable one-way clutch is further capable of producing a driving connection between an input member and an output member in one or both rotational directions and is also able to freewheel in one or both rotational directions as needed. As an example, a selectable one-way clutch may be implemented to transfer torque from an engine to the transmission, and to interrupt the transfer of reverse torque from the transmission to the engine.
Typical selectable one-way clutches in automatic transmissions often employ a high pressure hydraulic control system that is used to actuate the selectable one-way clutch. However, there are applications, such as hybrid electric vehicles, that may not otherwise require a high pressure hydraulic control system. Thus, there is a need for a new and improved selectable one-way clutch that does not require a high pressure hydraulic system for actuation.